The enormous influence of Isaac Newton on the intellectual life of Enlightenment Europe needs no elaboration. To both his English contemporaries and to the succeeding generation of natural philosophers who carried on his work, 'the incomparable Mr. Newton'1 was a towering figure  a testament to the greatness of the human mind. By the sheer power of thought, Newton had uncovered not only the nature of light, but also the riddle of the heavenly bodies, describing their movements with a simple set of physical laws, thereby overcoming two intractable problems that had puzzled scholars since antiquity. His achievements heralded a new faith in man's ability to unveil the mysteries of the natural world. Consequently, in the words of one contemporary scholar, "his influence was unprecedented in its extent and its comparative immediacy."2

Newton's great success with the problems of natural philosophy meant that subsequent generations of English natural philosophers understandably sought to apply Newtonian principles and Newtonian methods in a wide range of fields, from chemistry and physiology to morality and the study of electricity. Newton's intellectual authority extended even to matters of religion, where his use of the argument from design influenced a whole generation of natural philosopher-theologians bent on showing that the emerging scientific method could be used to demonstrate the truths of revealed religion. In this paper, I discuss Newton's influence on natural theology in late seventeenth and eighteenth century England. I argue that his influence gave rise to a synthesis of natural philosophy and natural religion, and that this synthesis was in turn the basis of a close and endurant alliance between Newtonianism and established Christian theology, differing from anything on the Continent in its extent and longevity.

Newton's God

It is now well known that like many natural philosophers of his time, Newton was much concerned with the relationship between God and the natural world.3 The scholarship on his unpublished papers in the past sixty years or so has entirely done away with the long prevalent image of Newton as an essentially positivistic modern scientist. Newton, it turned out, devoted substantial parts of his life to the study of alchemy, Scripture and the occult, and was committed to a peculiar brand of millenarian anti-Trinitarian Christianity. A devoutly religious man who in his life wrote almost as many theological dissertations as works of science, Newton did not merely append a deity to his physics as a show of fidelity, or as a convenient stop-gap to explain what his science could not. God played an active part in the universe, integrating with his natural philosophy in important ways.4

In the "General Scholium" at the end of the second edition of the Philosophiae Naturalis Principia Mathematica, Newton invoked the argument from design as evidence of the workings of God. As the man who had solved the 'riddle of the heavens', he was in a position of great authority when it came to interpreting the heavens themselves in the context of natural theology. Echoing Copernicus' rhetoric in the preface to De Revolutionibus Orbium Coelestium (1543), Newton argued that the motion of the heavenly bodies, "this most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being."5 The universe was the dominion of God, and demonstrated not only His existence, but also His greatness and perfection. Newton was confident that indisputable empirical facts about the physical world, open to anybody's observation, demonstrated without qualification the existence of God.6 Thus, he wrote that

we know [God] only by his most wise and excellent contrivances of things, and final causes; we admire him for his perfections; but we reverence and adore him on account of his dominion.7

Although this passage might seem to suggest a rather remote Being, recognisable to us only through his works, Newton's God was not the abstract creator-deity of radical deists such as Toland and Tindal.8 Newton's conception of divine activity in the world was informed as much by his intense studies of the Bible as his natural philosophy.9 It was of great concern to him to refute any materialistic or atheistic implications of his new natural philosophy and, like many anti-materialists before him, he did so by associating physical space and all movement therein with the intimate presence of God.10 According to Newton, the matter of which the world was composed was by nature inert, and only through the workings of the Supreme Being did it exert an attractive force. "The motions of the planets," he maintained, "could not spring from any natural causes, but were impressed by an intelligent agent."11 In other words, scientific facts about the physical world clearly implied a deity.12

Since the proper domain of the natural philosopher was the study of the physical world, natural theology too was therefore his province, insofar as the laws and properties of nature could be used to infer the existence of God. Thus, the natural philosopher, as conceived by Newton, had the additional task of gleaning knowledge of the deity through the examination of divine craftsmanship:

[There is] much concerning God; to discourse of whom from the appearances of things, does certainly belong to Natural Philosophy.13

Newton was not the first to detect that the new natural philosophy could  and should  be put to use in demonstrating the existence of a deity. Defenders of religion had quickly perceived the usefulness of re-emphasising Thomas Aquinas' "Fifth Way", given the increasing influence of empiricism and experimentation in natural philosophy throughout the seventeenth century. In England, perhaps the best known work of natural theology was The Wisdom of God Manifested in the Works of the Creation (1691), in which the pastor John Ray took "heavenly Bodies, Elements, Meteors ... &c." to be clear and unambiguous evidence of a designer.14 Newton's invocation of the design argument, however, lent it something that the writings of John Ray and his fellow clerics could not  namely, the considerable prestige of his "genius, and immortal fame."15 The great Newton, it seemed, had used his towering intellect to infer the existence of God from the nature of the physical world.

Newtonian Philosophy as a Bulwark Against Materialism and Atheism

Following the publication of the Principia in 1687, many English natural philosophers and clergymen quickly seized on the fact that the new philosophy might be used to stem what they believed to be a rising tide of irreligion, which they saw as rooted in materialist philosophies both homegrown and from the Continent, originating in the writings of Hobbes, Descartes and Spinoza. Of these scholarly defenders of the faith, the Boyle lecturers were probably the most influential. The natural philosopher Robert Boyle had left an annual sum in his will for lectures demonstrating the truth of the Christian religion "against notorious infidels,"16 and in the last decade of the seventeenth century, Newtonian natural philosophy was enthusiastically adopted for this purpose. There was much in Newton's work that was open to different interpretations, and his own remarks on the subject were at times ambiguous. The Boyle lecturers  notably Samuel Clarke, Richard Bentley and William Whiston  therefore set about proving the existence of God by firmly resolving any ambiguities in Newton's philosophy in favour of a Christian God actively participating in the workings of nature.17 Samuel Clarke, a close friend of Newton, ascribed the operation of gravity, which had been a source of contention between Newton and Leibniz, to the active participation of a deity in the workings of nature. At every moment, the mechanism of attraction between bodies depended on a Supreme Being actively imbuing matter with attractive force. Another Boyle lecturer, Richard Bentley  Newton's successor to a chair at Cambridge  heartily endorsed his belief in the existence of a divine maker who was particularly "well skilled in mechanics and geometry,"18 deducing this from the mathematical elegance of the inverse-square law of attractive force between bodies. Bentley also argued, against the Epicurean materialist theory, that the world was the product of a random collision of atoms, maintaining that the paucity of matter in the Newtonian universe made it well nigh impossible that it should have aggregated in such a way as to create the Earth and the heavenly bodies without divine intervention.19

Newton seems to have been pleased that his natural philosophy was being used to defend religious belief, remarking in a letter to Bentley that

when I wrote my treatise upon our Systeme I had an eye upon such principles as might work when considering men for the beliefe of a Deity and nothing can rejoyce me more than to find it usefull for that purpose.20

Thus, the relatively rapid adoption and full Christianisation of Newton's philosophy by men of the established Church took place with Newton's blessings. He may perhaps have recognised the value of pre-empting potential materialist interpretations of his work, given the association of Cartesian natural philosophy with atheism and materialism.

The Marriage of Natural Theology and Natural Philosophy

While it might well be expected that Newton's natural philosophy would be seized upon by Anglican divines for the purpose of defending religion, arguments from design seem to have been disseminated as part and parcel of Newton's philosophy, both by those in orders and those without. This is evident in contemporary works of Newtonian science, which clearly demonstrate a new marriage between natural philosophy and religion. The early eighteenth-century writers on Newton's natural philosophy seem to have been largely at one with Aristotle in believing that "to treat of the world without saying anything of its Author would be impious."21 Most of them freely mixed the arguments of natural religion  both Newton's and their own  with the new natural philosophy.

An early exposition of Newtonianism, George Cheyne's Philosophical Principles of Natural Religion (1705), is a good example of this mixture. Cheyne discussed the application of Newtonian principles to medicine, while spelling out the theological implications of Newton's work  namely, that the world was the product of a divine intelligence. "All of nature," he said, "supposes Design and Contrivance, and consequently is a sign of Production or Creation."22 It was quite impossible that the elaborate mechanism observable at work in the world could "have been the Effect of Chance and Casualty."23 Given the physical laws discovered by Newton, Cheyne thought the existence of God obvious to any "Man of ordinary Understanding, who has seriously set about the matter, and has duly weigh'd the Evidences."24 The presence of the handiwork of a great Deity, he said, was no less evident to the natural philosopher than the truth of the theorems of Euclid were to a student of geometry.25

Colin Maclaurin, another popular writer on Newton's work, argued in much the same vein. Demonstrations of the existence of God, he maintained, stood in "no need of nice or subtle reasoning."26 To him, like Cheyne, the "[design] arguments for the existence of the Deity" were obvious and absolutely compelling, "carrying irresistible conviction ... evident from the contrivance of things."27 Aside from the indisputable complexity and design observable in nature, "the simplicity of the laws that prevail in the world," described by the great Newton, were enough to indicate the handiwork of a Divine Author.28

Even those scholars who were relatively unconcerned with theological matters would make use of arguments from design, if only to justify their scientific work. This can be seen in the work of Henry Pemberton, Newton's friend and editor. In his View of Sir Isaac Newton's Philosophy (1728), he by and large avoided elaborating on the theological implications of Newton's work, but still thought it fit to observe in his preface that "the works of nature [offer everywhere] proofs of the unbounded power, and the consummate wisdom of their author."29

These early Newtonian texts indicate that in practice, natural religion was not clearly distinguished from natural philosophy, or at least not seen as a particularly distinct avenue of enquiry. The two seem to have formed a synthesis where the one reinforced the other, to the benefit of both. Newtonian natural philosophy was assimilated into the intellectual establishment of Anglican Christianity, and was thus protected, at least in part, from association with atheism and materialism, while Christianity could invoke the authority of the new natural philosophy both in matters concerning the existence of God  and, by rather questionable extension, in confirming the truths of revealed religion. Just as Platonic Christian theology and Aristotelianism had coalesced in the thirteenth century to form a comprehensive Christian world view where everything had its place  the Great Chain of Being30  so the combination of Newtonian natural philosophy and natural theology created a particular teleological conception of the world well suited to its time and place  one in which evidence of a purposeful Christian Creator-God could be found everywhere in nature. So pervasive was this development that throughout the eighteenth century and well into the nineteenth, English scholars and clergymen alike would continue to attribute natural phenomena in fields as diverse as natural history, anatomy and chemistry to the craftsmanship and providence of God.31

"The Cradle of Natural Theology"

This Newtonian strain of natural theology was largely, but not uniquely, an English phenomenon. It also rose to prominence in other Protestant countries such as Germany and the Netherlands, both of which developed their own traditions in natural theology. Natural theology in these countries, however, did not become as intimately tied with the very pursuit of natural philosophy as in England.32 The English seem to have been aware that the intimacy between religion and the investigation of nature was a homegrown phenomenon that was "particularly prominent and persistent"33 in their country. By the middle of the eighteenth century we find, for example, Thomas Nugent, the translator of Montesquieu's Spirit of Laws, describing England as "the cradle of natural religion."34

While eighteenth-century England abounded with natural theological works of varying quality, relatively few seem to have had much interest in pursuing this new intellectual avenue in Catholic France. Abbé Noel-Antoine Pluche, a notable exception, produced the relatively popular Spectacle de la nature (1732), but natural theology as such did not entrench itself into the culture of the practitioners of French natural philosophy in the same way as in England.35 This may perhaps be traced to the fact that much of progressive French work in natural science took place outside of the universities, and often against the will of the Church.36 When Newtonianism began to make great headway in France, thanks partly to Voltaire's Lettres philosophiques (1733), it seems to have done so despite rather than because of the established church.

Conclusion

The particularly English Newtonian-Christian synthesis described here  its rise, longevity, and relative intellectual sturdiness  is in many ways understandable. It was, first of all, inclusive in terms of compatibility with creeds, and thus well suited to England, a country divided on matters of religious doctrine. Arguments from design and conceptions of divine providence in nature for the most part reinforced and were compatible with the many variants of Protestant Christianity, irrespective of their internal theological differences. This meant that natural theology could serve as a banner under which Dissenters and Anglicans alike marshaled forces against the perceived threat of atheism and materialism.37 Secondly, the alliance of Protestant Christianity and Newtonian natural philosophy meant that study of the natural world took place within the fold of established religion, not outside of it, and the keenest expounders of natural philosophy were often clergymen. This may have alleviated tensions between religion and the burgeoning natural philosophy.

Finally, for those who studied the natural world, natural theology could serve as a valuable method by which to justify views on nature that seemed to go against revealed religion. Any empirical inquiries into the mysteries of nature  no matter how seemingly contradictory to Scripture their result might be  could be justified, at least partly, by saying that the uncovering of nature's mysteries served to demonstrate divine providence and the greatness of God. It thus became a valuable way of deflecting religious criticism.38

On the whole, it is difficult to evaluate whether the "Newtonian synthesis" had a positive or negative effect on the progress of natural science. Regardless of its effects, it would last some two hundred years as a widespread intellectual conception of the world among English natural scientists, succumbing finally in the late nineteenth century, in the aftermath of the destructive blow dealt by the work of Charles Darwin. Flexible enough to adapt to new scientific advances and drastic social changes throughout a large part of the modern period, it remains an important episode in the long and tumultuous relationship between organised religion and inquiry into the workings of the natural world.

Newton, Isaac, Sir Isaac Newton's Mathematical Principles of Natural Philosophy and His System of the World. Translated into English by Andrew Motte in 1729. (Berkeley and Los Angeles: The University of California Press, 1962).